• Title/Summary/Keyword: SOIL DEPT

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Review of Evaluation Methods and Soil Quality Factors for Agriculture Soils (농경지 토양의 토질요소와 평가 방법의 검토)

  • Chung, Doug Young;Lee, Kyo Suk
    • Korean Journal of Agricultural Science
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    • v.32 no.2
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    • pp.243-253
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    • 2005
  • In agricultural ecosystem, soils which play important roles of storage and cycling of substances become a crtitical social problem due to rapid increase of contaminants with respect to our health. Soil as productivity should be interpreted as soil quality, that is important criteria in maintaining sustainable agriculture for production of safe food. Therefore, it needs to set the criteria of soil quality by considering environmental factors including relevant parameters which are involved in soil quality soil health because soils are widely distributed and have various characteristics such as physical, chemical, and biological propevties. Therefore, it requires intensive investigation of evaluation methods and development of related parameters for environmentally sound agriculture and safe soil management.

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A Study on the Growth Characteristics of Multi-layer Planted Trees through Growth Analysis - With a Focus on Seoul Forest Park -

  • Kim, Han Soo;Ban, Soo Hong
    • Korean Journal of Environment and Ecology
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    • v.29 no.2
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    • pp.279-291
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    • 2015
  • This study analyzed the growth characteristics of multi-layer planted trees through their growth analysis and attempted to present a management strategy. The subject of research is the Citizen's Forest Area of Seoul Forest Park located in Seoul City. Field surveys were conducted three times over eight years from 2005 when the Seoul Forest Park was created through 2013. Labels were attached to all trees in the target area, and their species, height and DBH were investigated. To identify the growth differences by trees in each area, a detailed tree location map was drawn up for use in the analysis. To check soil health, soil organic matter, soil pH and soil microbial activities were analyzed. It turned out that the growth of the multi-layer planted trees in the target area of research was higher than that of the trees in existing urban parks, and that it was similar to that of trees in natural forests. Through a field survey in the area with a remarkably low growth, high-density planting problem, soil was found to have excess-moisture and there was the problem of Pueraria lobata covering. As a result of the analysis of the soil, it was found that its organic content in the soil was lower; soil pH was higher; and microbial activities in the soil were lower when compared to that of natural forests.

Impacts of Rainfall Events and Distribution on Unsaturated Soil Slope Analysis (불포화 토사사면 해석에 대한 강우사상과 분포의 영향)

  • Kim, Jae-Hong;Kim, Ho-Kyum;Kim, Byeongsu;Park, Seong-Wan
    • Journal of the Korean Geotechnical Society
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    • v.32 no.1
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    • pp.35-43
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    • 2016
  • The time distribution of rainfall is one of the most important considerations for evaluating soil slope stability. In order to study the rainfall-induced slope failure, the rainfall pattern has generally been assumed as uniform rainfall intensity for rainfall duration. However, it should be noted that the time distribution of the design rainfall method has a significant effect on the soil slope instability. The study implemented Mononobe, Huff, and uniform method as three types of time distribution method of the design rainfall to estimate the factor of safety of soil slopes by rainfall duration. As a result, the difference of soil suction and unsaturated hydraulic properties in a soil by rainfall pattern was found through the application of an appropriate time distribution method to numerical simulation for rainfall-induced slope stability.

Comparison of Micro-Pipette Method and Hydrometer Method in Soil Particle Size Analysis (Micro-Pipette법과 Hydrometer법에 의한 토양 입경 분석의 비교)

  • Chung, Jong-Bae;Kim, Min-Kyeong;Kim, Bok-Jin;Kim, Kye-Hoon
    • Korean Journal of Soil Science and Fertilizer
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    • v.32 no.3
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    • pp.274-278
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    • 1999
  • Determination of soil texture, particularly the clay fraction, is an important measurement in most researches related with soil. In this study micro-pipette method For soil particle size analysis was compared with the standard hydrometer method. Micro-pipette method can eliminate the need for bulky laboratory equipment and long settling times associated with the standard hydrometer or pipette method. In the results of this investigation, the particle size data obtained with micro-pipette method were in good agreement with those found using standard hydrometer method. And with this method one person could run analysis much larger numbers of soil sample per day than with hydrometer method in relatively small laboratory space.

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Development of Soil Conditioner Using Wood Decay Fungus and Forest Residue (임지폐잔재와 목재부후균을 이용한 토양개량제의 개발)

  • Min, Kyeong-Heui;Kim, Jae-Young;Yoon, Young-Han;Park, Heon
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.1
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    • pp.61-67
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    • 2006
  • The purpose of this study was to develop soil conditioner using wood decay fungus. The effect of soil conditioner treated with SJ-28 fungus was tested by lettuce cultivation. Cultivating efficiency was investigated by the yield of lettuce. In the plot of soil conditioner treated with SJ-28 fungus (FPG) showed weight of lettuce leaves 4425 g of total yield which was greater than 2434 g shown in the control. Also the numbers of actinomyces and fungi were increased in the plot of soil conditioner treated with SJ-28 fungus (FPG), beneficial for soil. The number of bacteria showed decrease in FPG plot. FPG showed possibility as a soil conditioner.

Spatial-temporal Distribution of Soil Moisture at Bumreunsa Hillslope of Sulmachun Watershed Through an Intensive Monitoring (설마천 유역 범륜사사면의 토양수분 시공간 집중변화양상의 측정)

  • Lee, Ga-Young;Kim, Ki-Hoon;Oh, Kyung-Joon;Kim, Sang-Hyun
    • Journal of Korea Water Resources Association
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    • v.38 no.5 s.154
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    • pp.345-354
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    • 2005
  • Time Domain Reflectometry (TDR) with multiplex system has been installed to configure the spatial and temporal characteristics of soil moisture at the Bumreunsa hillslope of Sulmachun Watershed. An intensive surveying was performed to build a refined digital elevation model (DEM) and flow determination algorithms with inverse surveying have been applied to establish an efficient soil moisture monitoring system. Soil moisture data were collected through intensive monitoring during 380 hrs in November of 2003. Soil moisture data shows corresponding variation characteristics of soil moisture on the upper, middle and lower parts of the hillslope which were classified from terrain analysis. Measured soil moisture data have been discussed on the context of physical process of hydrological modeling.

Performance Test of a Real-Time Measurement System for Horizontal Soil Strength in the Field

  • Cho, Yongjin;Lee, DongHoon;Park, Wonyeop;Lee, Kyouseung
    • Journal of Biosystems Engineering
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    • v.41 no.4
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    • pp.304-312
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    • 2016
  • Purpose: Soil strength has been measured using a cone penetrometer, which is making it difficult to obtain the spatial data required for precision agriculture. Our objectives were to evaluate real-time horizontal soil strength (RHSS) to measure soil strength in real time while moving across the field. Using the RHSS data, the tillage depth was determined, and the power consumption of a tractor and rotavators were compared. Methods: The horizontal soil-strength index (HSSI) obtained by the RHSS was compared with the cone index (CI), which was measured using a cone penetrometer. Comparison analysis in accordance with the measurement depth that increased at 5-cm interval was conducted using kriged maps at six sensing depths. For tillage control and evaluation of the power consumption, the system was installed with a potentiometer for tillage depth, a torque sensor from the rear axle, and a power take-off (PTO) shaft. Results: The HSSI was lower than the CI, but they were the same at 54.81% of the total grids for the 5-cm depth and at 3.85% for the 10-cm depth. In accordance with the recommended tillage map, tillage operations between 0 and 15 cm left 2.3% and 7% residue cover on the soil, and that between 20 and 10 cm covered a wider utilization of 3% and 18.4%, respectively. When the tillage depth was 15 cm, the comparison result of the power requirements between the PTO and rear axle in terms of control performance revealed that the maximum power requirements of the axle and PTO were 44.63 and 23.24 kW, respectively. Conclusions: An HSSI measurement system was evaluated by comparison with the conventional soil strength measurement system (CI) and applied to a tractor to compare the tillage power consumption. Further study is needed on its application to various farm works using a tractor for precision agriculture.